1. Field of the Invention
The present invention relates to a solid-state image sensing device, a method of fabricating the same, and a semiconductor device and, more particularly, to the construction of vertical charge transfer regions for transferring signal charges, associated with respective vertical rows of a plurality of sensor regions arranged in two-dimensions, a method of fabricating the vertical charge transfer regions, and a semiconductor device comprising a layer of a hydrogen storage alloy.
2. Description of Related Art
In a solid-state image sensing device, such as a charge-coupled image sensor (CCD), a plurality of sensor regions are arranged in two-dimensions, and vertical transfer lines for vertically transferring signal charges provided by the sensor regions are connected to respective vertical rows of the sensor regions. As shown in FIG. 6, in the vertical transfer line, a gate electrode 64 is formed near sensor regions 62 on a silicon dioxide film 63 formed on a silicon substrate 61, a polycrystalline oxide film 65 is formed over the gate electrode 64, a interlayer insulating layer 66 such as a PSG (phosphate glass film) is deposited over the polycrystalline oxide film 65 by an atmospheric pressure CVD process, and a light shielding layer 67 of a metal film of aluminum or the like is formed over the surface the interlayer insulating layer 66, excluding areas corresponding to the sensor regions 62, to shield a signal charge transfer layer 68 from external light.
When forming the light shielding layer 67 of a metal film after forming the interlayer insulating layer 66 by an atmospheric pressure CVD process in fabricating the charge-coupled image sensor of the aforesaid construction, damage attributable to sputtering or plasma is caused, and impurities diffuse through the interlayer insulating layer 66 into the interface between the silicon substrate 61 and the silicon dioxide film 63 and into the silicon substrate 61 during film forming processes and film processing processes to increase defects in the charge-coupled image sensor.
If the interlayer insulating layer 66 is formed with a comparatively large thickness to obviate such a problem, the quantity of light reflected by the surface of the silicon substrate 61 and falling on the lower surface of the light shielding layer 67 increases when light falls obliquely on the sensor regions 62. Consequently, the reflected light repeats with a multiple reflection between the surface of the silicon substrate 61 and the lower surface of the light shielding layer 67 and between the surface of the silicon substrate 61 and the gate electrode 64, and finally impinges on the signal charge transfer layer 68 to make the signal charge transfer layer 68 emit photoelectrons, which add to smear.